Production of lactones

ABSTRACT

CYLIC KETONES ARE REACTED WITH HYDROCARBON HYDROPEROXIDES TO PRODUCE LACTONES (CORRESPONDING TO THE KETONES) AND ALCOHOLS (CORRESPONDING TO THE HYDROPEROXIDES). FRIEDEL-CRAFTS CATALYSTS IMPROVE SELECTIVITIES TO THE DESIRED PRODUCTS. THE LACTONES MAY BE FURTHUR REACTED TO PRODUCE LACTAMS, AND THE ALCOHOLS MAY BE DEHYDRATED TO OLEFINS.

United States Patent 3,660,433 I i r :a'PRODUCTION' 0F LACTONES Jean Margaret .;Mallan and Edward Leo Kay, Akron,

Ohio, assigiiors to The Firestone Tire & Rubber Com- No.Drawing;:Continuation-inepartrof abandoned application S er No. 866,716, Oct. 15,1969. This application Sept. 18, 1970, Ser. No. 73,611

Claims CROSS-REFERENCE TO RELATED APPLICATION This application'is a continution-in-part of our copending-application Ser. No. 866,726, filed Oct. 15, 1969,

now abandoned, entitled Production of Lactones.

' BACKGROUND; ,OF, THE INVENTION This invention relatesto a process for the production of lactones. Specifically, it relatessto the production of lactones bythe-oxidation of c'yclic;ketones with organic hydroperoxides. x I

The oxidation of cyclic ketones with peracids to give lactones is well "known in the art. Some of the peracids employed as peracetic acid, persulfuric acid, perbenzoic acid, andiperoxytrifiuoroacetic acid. In these reactions, theperacid. is itself-.reduoedand the corresponding acid appears as a reaction product Reference 'is'also found in th'e literature to studies of the interaction of cyclic ketones with organic hydroperoxides in which a variety of reaction products are formed. One of such studies may be found in the book, Liquid Phase Oxidation of Hydrocarbons, Emanuel et al., Plenum Press, New York (1967), at pp. 84-86. The reaction as described in principally one of the decomposition of the hydroperoxide and its addition to the carbonyl group of the ketone. No catalyst was apparently employed, and the process is impractical for producing lactones.

SUMMARY OF- THE INVENTION {It is an object ot this invention "to provide a process for the production of lactones by reacting cyclic ketones with organic ll'ydroperoxides to give relatively high yields of lactones. It is another object of the invention to employ secondary or ter iar jhydrocarbon hydroperoxides irrtheoxidation of cyclic ketones-to lactones so as to The lsecondaryaontertiary "hydrocarbon hydroperoxides used in the invention can be acyclic hydrocarbon hydroperoxides of from 3 to 10 carbon atoms, such as propane-Z-hydroperoxide butane-Z-hydroperoxide 2-methylpropane-2-hydroperoxide Z-methylbutane-Z-hydroperoxide 2-methylbutane3-hydroperoxide pentane-Z-hydroperoxide pentane-3-hydroperoxide Z-methylpentane-Z-hydroperoxide 2-methylpentane-3-hydroperoxide 2-methylpentane-4-hydroperoxide 3-methylpentane-Z-hydroperoxide 3-methylpentane-3 -hydroperoxide hexane-Z-hydroperoxide hexane-B-hydroperoxide 2,2-dimethylbutane-3-hydroperoxide 2,3-dimethylbutane-2-hydroperoxide 2,2,3-trimethylbutane-3-hydroperoxide 3-ethylpentane-3 -hydroperoxide 1-butene-3 -hydroperoxide 2-methyl-3-butene-2-hydroperoxide Z-methyl-l-butene-3-hydroperoxide 2-methyl-2-butene-3-hydroperoxide 2,3-dimethyl-3-butene-2-hydroperoxide 3-ethyl-3abutene-2-h'ydroperoxide etc.

Aromatic hydroperoxides represented by the general formula can also be used, where R is phenyl or alkylphenyl, the alkyl group containing l-l2 carbon atoms, and R and R are hydrogen, al-kyl, aryl, or alkaryl, totaling from 1 to 18 carbon atoms. R and R cannot both be hydrogen, however,'examples of the aromatic hydroperoxides of the invention are ethylbenzene hydroperoxide cumene hydroperoxide diphenylmethane hydroperoxide triphenylmethane hydroperoxide bis (nonylphenyl) methane hydroperoxide tris (nonylphenyl) methane hydroperoxide, etc.

The Friedels-Crafts catalysts recommended for use in the process of the invention include the following:

Fluorides, chlorides, bromides, iodides of metals such as boron, aluminum, iron, zinc, zirconium, etc. Protonic acids of the Lewis Bronsted type such as sulfuric, hydrofluoric, pyrophosphoric, etc. are also recommended.

Generally, all types of Friedel-Crafts catalysts should be effective to a greater or lesser degree. A general description of these Friedel-Crafts catalysts is presented in Friedel-Crafts And Related Reactions edited by George A. Olah; volumes I to IV, Interscience Publishers. The reaction preferably proceeds at temperatures of 0 to 100 C.','more preferablyuat from 30 to C.

At these temperatures the reactiori vvill normally be in the well as the oxygen, chloro-, amino, nitro-, or sulfur derivatives of the aliphatic or aromatic hydrocarbons.

The lactones produced according to the process of the invention are useful in several applications. They may be further reacted with amines or anhydrous ammonia to convert them to corresponding lactams, which in turn may be polymerized to useful polymers; for example, caprolacetone may be converted to caprolactam, the starting material for the production of nylon 6.

The other primary products of the reaction of the invention will be the secondary or tertiary alcohols which may be recovered and used as such, or may be further reacted to dehydrate them to the corresponding olefins. In the case when a hydroperoxide of the empirical formula C H O is used, the primary product will be unsaturated alcohol; specifically, an allylic alcohol which can easily be dehydrated to a diolefin. If an aromatic hydroperoxide is used, the product will be an aromatic-substituted aliphatic alcohol. This alcohol can also be dehydrated to an aromatic-substituted olefin.

Selection of the particular hydroperoxide to be used can thus be dictated by the olefin desired on dehydration. Of particular interest are polymerizable olefins and diolefins such as styrene, isoprene and the like. Dehydration of alcohols can be performed in any of the known procedures, such as by heating with an appropriate catalyst.

' 4 1 1 g" formed. The selectivity figure for tertiary-butylhydroperoxide represents the formation of tertiary-butyl alcohol. The results summarized in Table I demonstrate that the reaction of a cyclic ketone (cyclohexanone) with tertiarybutylhydroperoxide to form lactonic products (caprolactone, epsilon-hydroxycaproic acid and polycaprolactone) is relatively slow in the absence of a catalyst (Example l). The reaction proceeds primarily to conversion of the hydroperoxide to tertiary-butyl alcohol. l

Examples Number 2 and 3 in Table I demonstrate that a Friedel-Crafts type. catalyst (in this instance, sulfuric acid and aluminum chloride) unexpectedly increases. the conversion of cyclohexanone as Well as the selectivity to lactonic products. I

In Examples 2 to 4 inclusive, in whichFriedel Cra'ft s type catalyst were used, the conversion of tertiary-butylhydroperoxide to tertiary-butyl alcohol was also significantly increased. The indicated selectivity to tertiarybutanol is believed to be low becausethe alcohol in acid medium is rather easily dehydrated to isobutene. The analytical procedures employed were such that isobutene was not analyzed.

Additional experiments were conducted to illustrate the general applicability of using Friedel-Crafts type catalysts for efiecting the reaction of cyclic ketones with hydroperoxides to form lactonic products.

The data derived from these experiments are summarized in Table H following.

TABLE II.VARIATION OF FRIEDEL-CRAFTSOATALYSTS Tertiary-butyl- Cyclohexanone, hydroperoxide,

mole percent mole percent Example Convcr- Selcc- Conver- Selec- No. Catalyst system sion tivity sion tlvity 5... No catalyst 2 0 9 71 6 H SO /A1Cl 18 90 i 75 r 40 7. Amberlite exchange resin IR-RO..- 8 83 -33 10 8 HzSO4/AlC1 /sec-butan0l 96 10 17 DESCRIPTION OF THE PREFERRED EMBODI- MENTS OF THE INVENTION The following examples are provided for purposes of illustration, and are not to be construed as limiting the invention, which is defined by the appended claims. Unless otherwise indicated, all percentages are by weight.

EXAMPLES Example Number 7 illustrates that a strong acid 40 exchange resin will also increase the selectivity of cyclohexanone to lactonic products.

Example Number 8 was included to demonstrate thata polar solvent (sec.-butanol) also has a beneficial etfect by increasing the rate of reaction.

EXAMPLE 1 9 In a manner similar to Examples 1 through'8, cyclobutanone, cyclopentanone, cycloheptanone, cyclooctanone and cyclododecanone are reacted with ethylbenzene hydro peroxide, l-butene-3-hydroperoxide and cumene hydroperoxide, in the presence of various Friedel-Crafts cata-v lysts to produce significant yields of the corresponding lactonic products, and the corresponding alcohols. The reactions are conducted at various temperatures between 0 and 100 C.

The reaction products are separated, and the alcohols dehydrated to the correspondingolefins by heating in the presence of alumina. Y

TABLE I.CYCLOHEXANONE CONVERSION TO LACTONIC PRODUCTS Tertlary-butyl- Cyclohexanone, hydroperoxide, mole percent mole percent Example Conver- Selec- Conver- Selec- No. Catalyst system sion tivity sion tivity 1 No catalyst 2 0 9 71 2.-. Sulfuric acid 16 31 22 3..- Aluminum chloride 10 12 31 41 4 Sulfuric acid/aluminum chloride..... 18 90 75 40 The conversion figure in each case represents the amount of that reactant which was chemically converted during the reaction (expressed in mole percent). The selectivity figure for cyclohexanone represents the mole percentage of lactonic products (as hereinbelow defined) EXAMPLE l0 In a manner similar 'to Examples through 9, cyclohexanone is reacted inturn with the hydroperoxides derived from the three isopentene isomers in the presence of various Fnedcl-Crafts catalysts to produce caprolactone and isomeric isopentyl alcohols. On separation of the reaction products, the alcohols are dehydrated to produce isoprene and its isomers.

EXAMPLE 11 In a similar manner as the preceding examples, cyclohexanone is reacted in turn with the hydroperoxides derived from Z-inethylbutane. On separation of the reaction products the five-carbon alcohols are dehydrated to give various isoamylenes.

We claim:

1. The process of reacting a cyclic ketone with a secondary or tertiary hydrocarbon hydroperoxide of from 3 to 12 carbon atoms in the presence of a Friedel-Crafts catalyst at a temperature of from 0 C. to 100 C. to produce the corresponding cyclic lactone and the correspondin g secondary or tertiary alcohol.

2. The process of claim 1, wherein the ketone is cyclohexanone, and the lactone is caprolactone.

3. The process of claim 1, wherein the hydroperoxide is tertiary-butyl hydroperoxide, and the alcohol is tertiarybutyl alcohol.

4. The process of claim 1, wherein the Friedel-Crafts catalyst is comprised of AlCl and sulfuric acid.

5. The process of claim 1, wherein the ketone is cyclobutanone, cyclopentanone or cycloheptanone.

6. The process of claim 1, wherein the ketone is cyclooctanone or cyclodedecanone.

7. The process of claim 1, wherein the hydroperoxide is ethylbenzene hydroperoxide, 1-butene-3-hyroperoxide, cumene hydroperoxide, or an isopentene hydroperoxide.

8. The process of claim 7, and the additional steps of separating and dehydrating the secondary or tertiary alcohol to the corresponding olefin.

9. The process of claim 1, wherein the hydroperoxide is 2 methylbutane-Z-hydroperoxide or 2-methylbutane-3- hydroperoxide.

10. The process of claim 9, and the additional steps of separating and dehydrating the isoamyl alcohols formed to isoamylenes.

References Cited UNITED STATES PATENTS 1,799,536 4/1931 Ruzicka 260-343 2,993,072 7/1961 ChiusOli et al 260-632 X 3,517,033 6/1970 Weiberg et a1 260-343 3,522,279 7/1970 Thigpen et al. 260-343 JOHN M. FORD, Primary Examiner US. Cl. X.R. 

